The followings are general notes for you.

- Always describe vendor's name and tool's name which you use.
- Don't do multiple posts which are same content.
- Don't request source code or behavioral model without any efforts.
- There are many simulators which have analyses called as PSS, PAC and Pnoise.
- Describe in detail with using correct terminologies.
- Warnigns are different from Errors.
- ADS is not name of simulator.
- There is no tool which name is Cadence.
- Don't use Direct Plot of Cadence ADE blindly without knowing definition.
- All gains in Direct Plot of Cadence ADE are "right", "true" and "practical" voltage gain.
- Don't mix up Simulation with Post Processing. They are completely different phase.
- MATLAB are different from Simulink.
- Learn measurements using actual instruments. Not "EDA Tool Play

ultimate wrote on Feb 19^th, 2010, 10:35am:

If you need physical modeling using R and C, you don't have to use Verilog-A.
And you can never generate complex poles if you use only R and C.

For behavioral modeling not physical modeling, what type of model do you need, bidirectional or unidirectional ?
Do you need input and output impedance ?
Is your requirement enough with signal flow model ?

For example, if we use S-parameter formulation, there are three options at least.

(1) Model expressing only S21.
(2) Model expressing {S11, S21, S22}.
(3) Model expressing {S11, S12, S21, S22}, that is, full model.

(1) and (2) are unidirectional.
(3) is bidirectional.

Marq Kole wrote on Mar 2^nd, 2010, 6:15am:
???????
What LPF do you want to realize ?

Don't you have typo for "V(n1, out) <+ 0;"



I think it should be : Quote:

This is "Signal Flow Model" for second order RC LPF.

Marq Kole wrote on Mar 2^nd, 2010, 7:21am:
I got.

ref = signal ground.

In most applications it will be connected to the vss, gnd, or whatever is your reference signal level.

Cheers,
Marq